Differential cytotoxicity of alternative forms of rotavirus nonstructural protein

摘要

The nonstructural protein 4 (NSP4) in the SA11 ATCC rotavirus strain has a histidine at amino acid position 47. This substituted form is more cytotoxic than the NSP4 of the Australia rotavirus strain, which has an asparagine at amino acid position 47. The histidine at amino acid position 47 is mutagenized to another amino acid to produce an alternative form of NSP4 which has reduced toxicity, while retaining its antigenicity and immunogenicity. NSP4 having a glutamic acid at amino acid position 48 is more cytotoxic than NSP4 having a lysine at amino acid position 48. The lysine at amino acid position 48 is mutagenized to another amino acid other than glutamic acid to produce an alternative form of NSP4 which has reduced toxicity, while retaining its antigenicity and immunogenicity.